I had the inheritance cycle stuff backwards. Oops!

1 files changed, 6 insertions, 4 deletions

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index a5779ef3fe..82237c870c 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -208,10 +208,12 @@ type_set_bases(PyTypeObject *type, PyObject *value, void *context)
 				type->tp_name, ob->ob_type->tp_name);
 			return -1;
 		}
-		if (PyType_IsSubtype(type, (PyTypeObject*)ob)) {
-			PyErr_SetString(PyExc_TypeError,
-		"a __bases__ item causes an inheritance cycle");
-			return -1;
+		if (PyType_Check(ob)) {
+			if (PyType_IsSubtype((PyTypeObject*)ob, type)) {
+				PyErr_SetString(PyExc_TypeError,
+			"a __bases__ item causes an inheritance cycle");
+				return -1;
+			}
 		}
 	}